He rode more securely than the rest, rising nobly like a horse of fine breeding, falling again with an implication of restrained force as though he would say: "I have only to let myself go and there, my word, you would see where I'd get to." His bold black eyes turned beseechingly to Jeremy--surely it was not only a trick of the waving gas; the boy drew closer and closer, never moving his gaze from the horses who had hitherto been whirling at a bacchanalian pace, but now, as at some sudden secret command, suddenly slackened, hesitated, fell into a gentle jog-trot, then scarcely rose, scarcely fell, were suddenly still.

Jeremy saw what it was that you did if you wanted to ride.

A stout dirty man came out amongst the horses and, resting his hands on their backs as though they were less than nothing to him, shouted: "Now's your chance, lidies and gents! Now, lidies and gents! Come along hup! Come along hup! The ride of your life now! A 'alfpenny a time! A 'alfpenny a time, and the finest ride of your life!" People began to mount the steps that led on to the platform where the horses stood.

A woman, then a man and a boy, then two men, then two girls giggling together, then a man and a girl.
And the stout fellow shouted: "Come along hup! Come along hup! Now, lidies and gents! A 'alfpenny a ride! Come along hup!" Jeremy noticed then that the fine horse with the black mane had stopped close beside him.

Impossible to say whether the horse had intended it or no! He was staring now in front of him with the innocent stupid gaze that animals can assume when they do not wish to give themselves away.
But Jeremy could see that he was taking it for granted that Jeremy understood the affair.